FRAMING AND CLOSING IN
Chapter 3FRAMING AND CLOSING INPageRecommended nailing practices . . . . . . . . . . . . . . . . . . 38Floor framing .38Factors in design ( 38 ), Sill plate ( 39 ),Posts and girders ( 39 ), Center beam ( 40 ),Built-up wood beams ( 41 ), SteelI-beams ( 41 ), Beam-joist installation ( 41 ),Floor joists ( 42 ), Header joist ( 45 ),Glued floor design ( 45 ), Bridging ( 47 ),Details at floor openings ( 47 ),Floor framing at projections ( 48 ),Framing details for plumbing, heating,and other utilities ( 49 ), Bathtubframing ( 49 ), Cutting floor joists ( 49 ),Framing for heating ducts ( 50 ),Wiring ( 50 ).Stairways .Types of sheathing ( 65 ), Comerbracing ( 71 ), Installation ofsheathing ( 71 ), Sheathing paper ( 72 ),Air infiltration barrier materials ( 72 ).Ceiling and roof framing .Roof sheathing .506183Plywood ( 83 ), Structuralflakeboard ( 84 ), Board( 84 ), Plank roofdecking ( 86 ), Fiberboard roofdecking ( 86 ),Gable ends ( 87 ),Chimney openings ( 87 ).Roof coverings .Plywood ( 61 ), Reconstituted woodpanels ( 62 ), Boards ( 62 ).Ice dams ( 88Built-up roofs (coverings ( 94ridge and hip (87), Shingles ( 88 ),94 ), Other roof), Finish at the94 ).Skylights .Exterior wall framing .12Roof designs ( 72 ), Manufacturedwood roof trusses ( 73 ), Ceiling joistsand rafters ( 78 ).Construction ( 50 ), Stairway design ( 52 ),Landings ( 54 ), Framing for stairwayopening ( 54 ), Service stairs ( 55 ),Main stairway ( 58 ), Attic foldingstairs ( 60 ), Exterior stairs ( 61 ).Floor sheathing .Exterior wall sheathing. . . . . . . . . . . . . . . . . . . . . . . . . . 659462Requirements ( 62 ), Platformconstruction ( 62 ), Second-storyframing ( 64 ), Window and doorframing ( 64 ).37
Framing and Closing InThe sections contained in this chapter address the tasksrelated to erecting the structural framing for the houseand creating an enclosure that provides some degree ofprotection from the elements.Figure 26 –Common nails.Recommended Nailing PracticesWood members are most commonly joined togetherwith nails, but on occasion metal straps, lag screws,bolts, staples, and adhesive can be used. Proper fasteningof frame members and covering materials provides rigidity and strength. For example, proper fastening of intersecting walls usually reduces cracking of plaster at theinside comers.The recommended number and size of nails, shown inthe technical note on nailing schedule, is based on goodnailing practices for the framing and sheathing of a wellconstructed wood-frame house. Sizes of common wirenails are shown in figure 26.Houses that are located in hurricane areas should beprovided with supplemental fasteners called hurricanestraps or tiedowns to anchor the floor, walls, and roof tothe foundation. Wind, snow, and seismic loads are one ofthe special topics discussed in chapter 8.Floor FramingFloor framing consists of columns or posts, beams, sillplates, joists, and subfloor. Assembled on a foundation,they form a level anchored platform for the rest of thehouse and a strong diaphragm to keep the lateral earthpressure from pushing in the top of the foundation wall.The columns or posts and beams of wood or steel thatsupport the joists over a basement are sometimes replacedby frame or masonry walls when the basement area isdivided into rooms. Floors of the second story are generally supported on load-bearing walls in the first story.Wood-frame houses may also be constructed over a crawlspace with floor framing similar to that used over a basement or on a concrete slab as shown in the section onfoundations.Factors in designAn important consideration in the design of a woodfloor system is wood shrinkage. When wood with a highmoisture content is used, subsequent shrinkage can resultin cracks, doors that stick, and other problems. This isparticularly important where wood beams are used,38because wood beams may shrink and foundation wallswill not. In beams and joists used in floor framing, moisture content should not exceed 19 percent; about 15 percent is a much more desirable maximum. Dimensionmaterial can be obtained at either of these moisture contents, when specified.Grades of dimension lumber vary considerably withwood species. For the specific uses described in this publication, material is divided into five categories. The firstcategory is the highest quality, the second is better thanaverage, the third average, and the fourth and fifth formore economical construction. Joists and beams areusually of a species of second category material, whilesills and posts are usually of third or fourth category.(See technical note on lumber grades.)Stairways and other openings that penetrate the floorstructure should be located so as to interrupt as few members as possible. Stairways should be oriented parallel tofloor joists so that only one joist need be interrupted with24-inch on-center joist spacing. Wherever possible, thestair opening should be coordinated with a normal joistlocation on at least one side. Stairways should neverinterrupt a structural beam or bearing wall when it canbe avoided.The stairway design should be completed before floorframing begins, because the stairwell opening must be
framed at the time the floor is constructed. The roughframed opening for a stairwell should be 1 inch widerthan the desired finished stairway width. The length ofthe opening must be accommodated to tread run and stairrise, which in turn are governed by total rise.Other openings such as those for clothes chutes and fluehole should also be located to avoid interrupting framingmembers. Two-foot on-center spacing of joists generallyprovides ample clearance for such openings.Sill plates may be entirely eliminated where the top of afoundation of poured concrete (fig. 27B) or concreteblock (fig. 28B) is sufficiently level and accurate. Joistsmay bear directly on a solid concrete wall or on a topcourse of solid concrete block. They may also beardirectly on cross webs of hollow core block or on coresthat have been filled with mortar. Where the sill plate isomitted, anchorage of the floor system may be providedby anchor strap devices, as described above. The strapsshould be spaced to coincide with joist locations so thateach may be nailed directly to the side of a joist (fig. 28).Sill plateA wood-frame floor system should be anchored to thefoundation to resist wind forces acting on the structure.This is usually done with a 2- by 6-inch sill plate attachedto the foundation by ½-inch anchor bolts at 8-foot intervals. Floor joists are toenailed to the sill plate (fig. 27A).The sill plate may also be attached with anchor straps thatare embedded in the foundation in the same manner andat the same spacing as anchor bolts. These devices do notrequire holes in the sill plate; metal straps are simply bentup around the plate and nailed. Anchor straps are lessexacting and do not interfere with other framing as conventional bolts often do.As noted previously, a foundation of pressure-treatedwood does not require a sill plate or special anchordevices. Floor joists bear directly on the top foundationwall plate and are toenailed to provide anchorage.Posts and girdersWood posts or steel columns are generally used in thebasement to support wood or steel beams. Masonry piers orwood posts are commonly employed in crawl-space houses.Steel pipe columns can be used to support either woodor steel beams. They are normally supplied with a steelFigure 27 – Anchoring floor system to poured concrete foundation wall:39
Figure 28 – Anchoring floor system to concrete block foundation wall:bearing plate at each end. Secure anchoring to the beamis important (fig. 29).Wood posts should be solid, pressure-treated, and notless than 6 by 6 inches in size for freestanding use in abasement. When combined with a framed wall, they maybe 4 by 6 inches to conform to the width of the studs.Wood posts should be squared at both ends and securelyfastened to the beam (fig. 30). The bottom of the postshould rest on and be pinned to a masonry pedestal 2 to 3inches above the finish floor.Center beamsWood-frame floor construction typically employs abeam or girder to provide intermediate support for thefirst floor. In two-story construction, the beam generallysupports the second floor as well via a load-bearing wallextending along the center of the first story.40For maximum benefit in reducing joist spans, beamsand bearing walls should be located along the centerlineof the structure. In some cases it may be desirable to offset the center support 1 foot from the centerline to provide for even-length joists; for example, in a 30-foot-deepfloor system, displace the centerline to 14 and 16 feetfrom the two sides instead of 15 feet from both. However, as discussed later, this is not necessary if off-centerspliced joists are used.The center beam usually bears on the foundation ateach end and is supported along its length by columns orpiers. The spacing of columns or piers is adjusted to thespanning capability of the beam for a particular design load.Two basic types of center beams-wood and steel-arecommonly used. The decision on which to use should bebased on a comparison of the total installed cost of each,including intermediate support columns or piers, and footings. Other considerations include delivery, scheduling,and ease of construction.
Figure 29 – Steel post support for wood or steel beam:For equal widths, the built-up beam is stronger than thesolid beam.Built-up wood beamsBuilt-up beams are constructed by nailing three or fourlayers of dimension lumber together. The built-up beammay be made longer than any of the individual membersby butting the ends of the members together. These buttjoints must be staggered between adjacent layers so thatthey are separated by 16 inches. In addition, the built-upbeam must be supported by a column or pier positionedwithin 12 inches of the butt joints (fig. 31).Typical allowable spans for built-up wood beams areshown in table 5 . Dry lumber should always be used toavoid settlement problems caused by shrinkage of thebuilt-up beam and the joists it supports. It is not necessary to use a wood plate over wood beams, because floorjoists can be nailed directly to the beam.Figure 30 – wood post support for wood beam:Ends of wood beams should bear at least 4 inches onthe masonry walls or pilasters. When wood is untreated, a½-inch air space should be provided at each end and sideof wood beams framing into masonry (fig. 31). The topof the beam should be level with the top of the sill plateson the foundation walls.Steel I-beamsSteel I-beams are often used because they have greaterstrength and stiffness than wood beams, which enablesthem to carry a given load over a given span with a beamof lesser depth and thus provides greater headroom orreduces the requirement for additional supporting posts.Allowable spans for steel I-beams are shown in table 6.However, steel beams require an additional supplier,which can complicate delivery schedules. They are alsoheavier and more difficult to handle in the field. The totalcost of a steel beam, including columns or piers, is generally greater than that of a wood beam.Where steel beams are used, a wood plate 2 by 4 or 2by 6 inches across is usually attached to the top surfaceby bolting or by driving nails part way into the sides ofthe plate and bending the protruding nail shanks over theedges of the beam flange. Floor joists are then toenailedto the beam plate to anchor to the floor and to providelateral bracing for the beam. A beam plate is not requiredif the floor joists are secured by other means.Beam-joist installationWood center beams are of two types, solid or built-up.The built-up beam is preferable because it can be madeup from dimension material that is drier and more stable.In the simplest method of floor framing, the joists beardirectly on top of the wood or steel beam. The top of thebeam coincides with the top of the foundation or anchoredsill, if the latter is used (fig. 31). This method assumes41
Figure 31 –Typical built-up wood beam installation.that basement wall heights provide adequate headroombelow the girder. When a forced-air heating system is tobe installed, this arrangement of beam and joists providesspace for the main duct to be run parallel to the beam andfor the laterals to be run between the joists above thelevel of the beam.As previously noted, beams and joists should be constructed of dry lumber to reduce problems caused by settlement resulting from shrinkage. This is of particularconcern when wood joists bear directly on top of the woodbeam at the center of the house while bearing on the concrete foundation wall at the outer ends. In order to equalizethe depth of wood at the beam and at the outer wall-andthereby equalize shrinkage potential-joistsshould beattached to the side of the wood beam using joist hangersor supporting ledger strips (fig. 32). The simplest methodis to use steel joist hangers (fig. 32A). Where ledgers areused, joists must always bear on the ledgers (fig. 32B). Itis important that a small space be allowed above the beamto provide for shrinkage of the joists.Joists may be butted to a steel beam in the samegeneral way as is illustrated for a wood beam, with joistsresting on a wood ledger that is bolted to the web (fig. 33).42Floor joistsFloor joists are selected primarily to meet strength andstiffness requirements. Strength requirements depend onthe load to be carried. Stiffness requirements place anarbitrary control on deflection under load. Stiffness is alsoimportant in limiting vibrations from moving loads-oftena cause of annoyance to occupants.Wood floor joists have generally nominal thickness of2 inches and nominal depth of 8, 10, or 12 inches. The sizerequired depends upon the loading, length of span, spacing between joists, and species and grade of lumber used.After the sill plates have been anchored to the foundation walls and the center beam installed, the joists are laidout according to the house design. The center-to-centerspacings most commonly used are 24 inches or 16 inches.Span tables for floor joists, provided by the NationalForest Products Association or in local building codes,can be used as guidelines. Table 7 is a simplified versionfor joists spaced 24 inches on center and table 8 for 16inches on center. The sizes shown in the table are minimal; it is sometimes desirable to use the next larger lumber size than that listed in the table.
Table 5 – Allowable spans for built-up wood center beamsLength of maximum clear spanMinimum requiredbending stress (9of 1,000 psiaMinimum requiredbending stress (9of 1,500 psibWidth ofBeamstructurecomposition(ft)One-story Two-story One-story Two-story32x842x832x1042x103 2 x 124 2 x 12Source: NAHB Research Foundation (1971). Manual of Lumber- and Plywood-SavingTechniques for Residential Light-Frame Construction.aThe bending stress (f) measures the strength and varies with the species and gradeof lumber as shown in the technical note on design values.b The allowable spans shown assume a clear-span trussed roof construction. In twostory construction, a load-bearing center partition has been assumed. The built-up woodcenter beam and/or the load-bearing partition in two-story construction may be offsetfrom the centerline of the house by up to 1 foot.Joists should be inspected for straightness visually, asthey are being placed. Any joists having a slight crookedgewise should be placed with the crown on top. Acrowned joist tends to straighten out when subfloor andnormal floor loads are applied. Those joists that are notcrowned should be inspected for the presence of knotsalong the edge. The largest edge knots should placed ontop, because knots on the upper side of a joist are placedin compression and have less effect on strength.The header joist is fastened by nailing through it intothe end of each joist with three 12d or 16d nails. In addition, the header joist and the stringer joists parallel to theexterior wall in platform construction (fig. 34) are toenailed to the sill with 10d or 12d nails spaced 16 incheson center. Each joist should be toenailed to the sill andTable 6 – Allowable spans between columns or pierssupporting steel center beamsaLength of maximum clearspanSteel beamdesignationb &total house width (ft)For 1-storyhouseFor 6283210017.02426283210W21.024262832Source: United States Steal Corporation (1980). Steel beam stress & deflection estimatorfor use in calculating sizes of laterally supported beams for residential and light construction.a Based on a continuous beam over two equal spans with a maximum of ½-inchdeflection at design load and assuming a clear span trussed roof.bThe steel beam designations presented are those most commonly available at building material suppliers. The designation gives the height of the beam in inches, a letterdesignating the type of I-beam, and the weight of the beam in pounds per linear foot.(An "8B10.0" I-beam is an Pinch-high type B I-beam that weighs 10.0 pounds per linear foot.)center beam with two 10d or three 8d nails, then nailed toother joists with three 12d nails where they lap over thecenter beam. If joists are butted over the center beamthey should be joined with a nominal 2-inch scab nailedto each joist with three 12d nails.An off-center splice may be used in framing floorjoists. This system often allows the use of one smallerjoist size when center supports are present. In off-centersplicing, long joists are cantilevered over the center support and spliced to short joists (fig. 35). The locations ofthe splices over the center beam are alternated. Dependingon the span, species, and joist size, the overhang variesbetween about 2 feet and 3 feet. Metal splice plates areused on each side of the joints. Selecting the proper platesize and installing the plate must be done by a trussfabricator.43
Figure 32–Joists butted to side ofwoodbeam:Table 7 – Allowable spans for simple floor joists spaced 24 inches on center for wood with modulus of elasticity values of1.0 to 2.0 x 10 6 pounds per square inch.Length of maximum clear span1.0 x106 psiLiving areas (40 Ib/ft2 live load)Minimum required bending1,050stress (Ib/in2)Joist size7' 3"2x62x89' 7"2 x 1012' 3"2 x 1214'11"Sleeping areas (30 Ib/ft2 live load)Minimum required bending1,020stress (Ib/in2Joist size8' 0"2x62x82 x 102 x 1210' 7"13' 6"16' 5"1.1 x106 psi1.2 x106 psi1.3 x106 psi1.4 x106 psi1.5 x106 psi1.6 x106 psi1.7 x106 psi1.8 x106 psi1.9 x106 psi2.0 x106 6707' 6"7' 9"7' 11"8' 2"8' 4"8' 6"8' 8"8' 10"9' 0"9' 2"9'11"12' 8"15' 4"10' 2"13' 0"15'10"10' 6"13' 4"16' 3"10' 9"13' 8"16' 8"11' 0"14' 0"17' 0''11' 3"14' 4"17' 5"11' 5"14' 7"17' 9"11' 8"14'11"18' 1"11' 11''15' 2"18' 5"12' 1"15' 5"18' 208' 3"8' 6"8' 9"8' 11"9' 2"9' 4"9' 7"9' 9"9' 11"10' 1"10' 11''13' 11"16' 11"11' 3"14' 4"17' 5"11' 6"14' 8"17'11"11' 10''15' 1"18' 4"12' 1"15' 5"18' 9"12' 4"15' 9"19' 2"12' 7"16' 1"19' 7"12'10"16' 5"19'11"13' 1"16' 8"20' 3"13' 4"17' 0"20' 8"Source: National Forest Products Association (1977). Span Tables for Joists & Rafters.Note: Use table 8 for joists spaced 16 inches on center.The modulus of elasticity (E) measures stiffness and varies with the species and grade of lumber as shown in the technical note on design values. The bending stress (f) measuresstrength and varies with the species and grade of lumber as shown in the technical note on design values.44
Table 8 – Allowable spans for simple floor joists spaced 16 inches on center for wood with modulus of elasticity values of1.0 to 2.0 x 106 pounds per square inchLength of maximum clear span1.0 x106 psi1.1 x106 psi1.2 x106 psi1.3 x106 psi1.4 x106 psi1.5 x106 psi1.6 x106 psi1.7 x106 psi1.8 x106 psi1.9 x106 psi2.0 x106 psiLiving areas (40 Ib/ft2 live load)Minimum required bendingstress (Ib/in2)Joist size2x62x82 x 102 x 12Sleeping areas (30 Ib/ft2 live load)Minimum required bendingstress (Ib/in2)Joist size2x62x82 x 102 x 12Source: National Forest Products Association (1977). Span Tables for Joists & Rafters.Note: Other tables should be used for other joist spacings.The modulus of elasticity (E) measures stiffness and varies with the species and grade of lumber as shown in the technical note on design values. The bending stress (f) measuresstrength and varies with the species and grade of lumber as shown in the technical note on design values.Figure 33 – Steel beam with joists bearing on ledger.Header joistsThe header joist, or band joist, used across the ends offloor joists, has traditionally been the same size as floorjoists. One function of a header joist is to brace floorjoists temporarily in position prior to application of thesubfloor. The header joist also helps to support stud loadsin conventional construction, where wall studs do notnecessarily align with floor joists.With modular planning, however, each wall stud shouldbear directly over a floor joist. A header joist nominally1 inch thick may therefore be used in place of the traditional 2-inch header. A header joist of lumber nominally1 inch thick uses less material and is easier to install with8d nails.Glued floor designJoists should be at least doubled under parallel loadbearing partition walls. Solid bridging should be used inplace of doubled joists when access from below is neededfor installing heating ducts in the load-bearing partition(fig. 34). It is not necessary, however, to double joistsunder parallel partitions not bearing load. In fact, it is notnecessary to locate a partition not bearing load over afloor joist; the floor sheathing is normally adequate tosupport the partition between joists (fig. 36).When a plywood subfloor is properly glued to floorjoists with a construction adhesive, the subfloor and floorjoists tend to act together as a single structural member.The composite T-beam thus formed can span a greaterdistance than a floor that is fastened only with nails.Glue-nailing of the plywood subfloor is recommendedas a cost-effective method of increasing the stiffnessand/or allowable space of a floor, as shown in table 9.Glue-nailing is also highly effective in reducing the floorsqueaks and loose nails that may otherwise develop lateras a result of shrinkage of joists.45
Figure 34-Typical platform construction.Figure 35 – Off-center spIiced joist system allows use of one short joist in every pair of joists.46
Figure 36 – Non-load-bearing partitions need no extra floor framing or blocking with 5/8-inch or thicker ply- wood floor.BridgingDetails at floor openingsBridging between wood joists is no longer required byany of the model building codes for normal house construction, that is, for spans not exceeding 15 feet and joistdepth not exceeding 12 inches. Even with tight-fitting,well-installed bridging, there is no significant transfer ofloads after subfloor and finish floor are installed. Bridgingalso increases the likelihood of floors squeaking if thesubfloor is not glued to the joists.Large openings in the floor, for items such as stairwellsand fireplaces or chimneys, usually interrupt one or morejoists. Such openings should be planned so that their longdimension is parallel to joists in order to minimize thenumber of joists that are interrupted. The opening shouldnot disrupt the center beam or bearing partition that supports the floor. Wherever possible, the opening should becoordinated with the normal joist spacing on at least one47
Table 9 – Allowable spans for joists with ¾-inch glued plywood flooring spaced 24 inches on center for wood withmodulus of elasticity values of 0.6 to 2.0 x 106 pounds per square inchLength of maximum clear span0.6 x106 psi0.8 x106 psi1.0 x106 psi1.2 x106 psi1.4 x106 psi1.6 x106 psi1.8 x106 psi2.0 x106 psiLiving areas (40 Ib/ft2 live load)2 x 6 joistsMinimum required bendingstress (Ib/in2)Maximum span2 x 8 joistsMinimum required bendingstress (Ib/in2)Maximum span2 x 10 joistsMinimum required bendingstress (Ib/in2)Maximum span2 x 12 joistsMinimum required bendingstress (Ib/in2)Maximum spanSleeping areas (30 Ib/ft2 live load)2 x 6 joistsMinimum required bendingstress (Ib/in2)Maximum span2 x 8 joistsMinimum required bendingstress (Ib/in2)Maximum span2 x 10 joistsMinimum required bendingstress (Ib/in2)Maximum span2 x 12 joistsMinimum required bendingstress (Ib/in2)Maximum spanSource: NAHB Research Foundation (1977). Reducing Home Building Costs with OVE Design and Construction.The modulus of elasticity (E) measures stiffness and varies with the species and grade of lumber as shown in the technical note on design values. The bending stress (9 measuresstrength and varies with the species and grade of lumber as shown in the technical note on design values.side to avoid the necessity for an additional trimmer joistto form the opening.A single header is generally adequate for openings upto 4 feet in width. A single trimmer joist at each side ofthe opening is usually adequate to support single headersthat are located within 4 feet of the end of joist spans(fig. 37). Tail joists under 6 feet in length may befastened to the header with three 16d end nails and two10d toe nails, or equivalent nailing. Tail joists over 6 feetin length should be attached with joist hangers. Theheader should be connected to trimmer joists in the samemanner as tail joists are connected to the header.Where wider openings are unavoidable, double headersare generally adequate up to 10 feet (fig. 38). Tail joistsmay be connected to double headers in the same mannerand under the same conditions as specified above for sin48gle headers. Tail joists that are end nailed to a doubleheader should be nailed prior to installation of the secondmember of the double header, to provide adequate nailpenetration into the tail joist. A double header shouldalways be attached to the trimmer with a joist hanger.Trimmer joists at floor openings must be designed tosupport the concentrated loads imposed by headers wherethey attach to the trimmer. As noted previously, a singletrimmer is adequate to support a single header locatednear the end of the span. All other trimmers should beat least doubled, and should be engineered for specificconditions.Floor framing at projectionsThe framing for wall projections such as a bay window,a wood chimney, or first- or second-floor extensions
Figure 37 – Floor opening framed with single header and single trimmer joists.beyond the lower wall should consist of the projection ofthe floor joists (fig. 39). This extension normally shouldnot exceed 24 inches. The subflooring is carried to andsawed flush with the outer framing member. Greaterprojections for special designs may require specialanchorage at the opposite ends of the joists.Projections at right angles to the length of the floorjoists should generally be limited to small areas andextensions of not more than 24 inches.' If the projectingwall carries any significant load, it should be carried bydoubled joists (fig. 39B). Joist hangers should be used atthe ends of members.In two-story houses, there is often a projection or overhang of the second floor for the purpose of architecturaleffect or to make second-floor siding flush with first-floorbrick veneer. This overhang may vary from 2 to 15inches or more. The overhang should ordinarily be onthat side of the house where joist extensions can supportthe wall framing (fig. 40). Such extensions should beprovided with insulation and a vapor retarder.When the overhang parallels the second-floor joists, adoubled joist should be located back from the wall at adistance about twice the width of the overhang to whichoverhang blocks are attached. These blocks rest on top ofand project beyond the outside wall.Framing details for plumbing, heating, and other utilitiesIt is desirable to limit cutting of framing members forinstallation of plumbing lines and other utilities. This ismore easily accomplished in one-story houses than in twostory houses. In a single-story house, most connectionsare made in the basement area; in two-story houses theymust be made within the second floor. When it is necessary to cut or notch joists, it should be done in a mannerleast detrimental to their strength. (For more details seethe section on cutting floor joists.)Bathtub framingA bathtub full of water is heavy and may cause excessive deflection of floor joists. A doubled floor joist shouldbe provided beneath the tub to support this load (fig. 41).The intermediate joist should be spaced to allow installation of the drain. Metal hangers or wood blocking shouldbe used to support the edge of the tub at the wall.Cutting floor joistsIt is sometimes necessary to cut, notch, or drill joists toconceal plumbing pipes or wiring (see below) in a floor.Joists or other structural members that have been cut ornotched can sometimes be reinforced by nailing a reinforcing scab to each side or by adding an additional member.Notching the top or bottom of the joist should be doneonly in the end one-third of the span and to no more thanone-sixth of the depth. When greater alterations arerequired, headers and tail joists should be added aroundthe altered area, as for a stair opening (fig. 37).49
Figure 38 – Floor opening framed with double header and double trimmer joists:When necessary, holes may be bored in joists if thediameter is no greater than one-third of the joist depthand the edge of the hole is at least 2 inches from the topor bottom edge of the joist (fig. 42).Framing for heating ductsForced air systems with large ducts for heating and airconditioning are becoming a standard part of house construction. Framing should be laid out with
construction ( 62 ), Second-story framing ( 64 ), Window and door framing ( 64 ). 37 Chapter 3 FRAMING AND CLOSING IN . Framing and Closing In The sections contained in this chapter address the tasks
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Fundmentals of building construction (2nd ed.). New York: Wiley & Sons. Framing Methods, Exterior Wall Construction FRAMING METHODS The most common framing systems used with wood are: Balloon Platform Post and beam . Framing Methods, Exterior Wall Construction BALLOON FRAMING (EASTERN) Is not widely used except for gable
FRAMING Build efficiently, use less material, and save energy! Advanced framing refers to a variety of framing techniques designed to reduce the amount of lumber used and waste generated in the con struction of a wood-framed house. ADVANCED FRAMING These techniques include Designing homes on 2-foot mod ules to make
3.1 Background on Framing Analyses While agenda-setting broadly refers to what topics a text covers, framing refers to which attributes of those topics are highlighted. Several aspects of framing make the concept difficult to analyze. First, just defining framing has been “notoriously slippery”(Boydstunetal.,2013).Framescanoccur
The major work that first distilled the idea of framing was Erving Goffman’s 1974 book Frame Analysis: An Essay On The Organization Of Experience. Goffman’s definition of a frame is: Framing Framing 2 “I assume that definitions of a situation are built up in accordance with principals of
3.2 Separate roof and wall framing plans Layout plans must convey information in a clear and concise manner as they need to be read and understood by a number of different people. When roof framing layouts and wall framing layouts are combined, too much information is shown on the one plan making the layout confusing and difficult to read.
The method of construction, stick framing or panelization, and type of project will have a direct bearing on the cost of the steel frame system. Stick Framing “Stick framing” is the method most commonly used to build wood framed homes today, and involves assembling the floors and walls using individual studs and joists on the construction site.
Accounting information from several branches can be merged, making decision-making easy and fast. End of Chapter Questions 1 Anti-virus software, complicated passwords. 2 Email, cloud. 3 You can save your work, easy to send to other people, calculations and templates are already there for you to use. 4 Hacking, failure in technology – power cut, some software is expensive. Exam Practice 1B .
